The body is lean and assumes competence — it does not re-explain backdrop-filter, mask-composite, or basic CSS, and every section (tokens, panel, border, Tailwind, checklist) earns its place.

Provides fully executable, copy-paste-ready CSS for tokens, .glass-panel, and .border-gradient::before, plus a complete Tailwind HTML snippet and concrete numeric guidance (e.g. 'at least #cbd5e1', '--glass-fill-strong').

A clear six-step sequence ends with an explicit validation checkpoint ('Validate contrast and mobile behavior before finalizing'), reinforced by the Dark Mode Checklist that supplies concrete validation criteria.

No bundle files exist or are needed for a self-contained CSS recipe; content is organized into well-delineated sections with clear headers, satisfying the simple-skill allowance for scoring 3 without external references.

Lists multiple concrete actions — 'readable contrast, frosted surfaces, and gradient borders using a pseudo-element mask' — going beyond naming the domain to specifying distinct capabilities.

Explicitly answers both what ('Build dark-mode glassmorphism interfaces...') and when ('Use when asked for...') with explicit triggers, satisfying the top anchor.

The 'Use when asked for glass cards, frosted dark hero sections, blur panels, or dark UI systems with gradient/glow borders' clause gives good coverage of natural terms users would actually say.

The dark-mode glassmorphism niche with gradient/glow-border triggers is clearly scoped and unlikely to fire for unrelated skills.